Adhesives containing mainly of a 2-cyanoacrylate, which has specific anionic polymerizability, strongly bond various materials to a substrate in a short time by initiating polymerization upon contact with a weak anion such as a small amount of water on the surface of the substrate. Therefore, they are widely used as so-called instantaneous adhesives for industrial, medical, household, and other purposes. These adhesives lead excellent shear adhesive strength, but their cured products are hard and brittle. Therefore, they have low peel strength and impact adhesive strength, and are particularly inferior the thermal shock resistance between bonded substrates of different materials. In order to solve these problems, various reforming methods including the addition of various elastomers and additives have been conventionally proposed in, for example, Patent Documents 1 and 2. Other known methods include the addition of a polyfunctional cyanoacrylate such as bifunctional cyanoacrylate to the adhesive in, for example, Patent Documents 3 and 4.                [Patent Document 1] JP-A H3-290484        [Patent Document 2] JP-A H6-57214        [Patent Document 3] JP-A H10-500968        [Patent Document 4] JP-A H11-302602        